Problems with the vacuum pump in the distillation tower
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The unit has one distillation tower, equipped with two liquid ring vacuum pumps. The process requires an absolute tower top pressure of 15 KPa. During the driving phase, a single vacuum pump was not sufficient to meet the process requirements; later, two vacuum pumps were used simultaneously, but the vacuum level could still only reach around 25 KPa. There are two reasons for this suspicion: first, at the beginning of operation, there is a higher proportion of light components at the top of the tower, which results in a greater load on the vacuum pump ； Second, there is a problem with the airtightness of the distillation tower. The unit is currently in a shutdown for maintenance phase; a vacuum pump is used to reduce the pressure inside the tower to around 25 KPa. After maintaining this pressure for 24 hours, the vacuum level rises to approximately 26 KPa absolute, which helps to eliminate any air leakage issues in the distillation tower. Then, when two vacuum pumps were operated simultaneously, it was found that the pressure could only reach around 25 KPa before further reduction was no longer possible. Please analyze what causes this
It’s a problem with the vacuum pump, I guess. Water ring vacuum pumps can achieve a limit vacuum of 3-4 Kpa without any issues; check the reasons related to the vacuum pump. Problems such as fillers, impellers, etc.
Problem with the pump; the pump selected cannot achieve the required level of vacuum
If the pressure holding is fine, then it’s a problem with the vacuum pump. It seems to be a product from a small factory, an inferior quality item.
Can a machine be set to draw a number below 25?
It could be a problem with the vacuum pump, or a leak in the return valve; it’s also possible that the gauge is broken :)
If the material supply is stopped, increasing the vacuum level by using a separate pump will not work either; it means the quality of the pump is inadequate； Otherwise, the vacuum pump is too small
There’s another place that I suggest checking. The “liquid” that enters the impeller in vacuum pumps also needs to be checked. This liquid stream, coming out of the gas-liquid separation tank, should pass through a filter and a cooler before entering the pump impeller, right? First: Clean the filters in the flow path to check if there is any dirt that is reducing the flow rate entering the pump impeller ； Second: Check the heat exchange performance of your cooler. We have temperature requirements for the liquid entering the pump impeller. Because if the liquid temperature is too high and enters the impeller, it will vaporize and get stuck there, preventing it from being expelled – which in turn will affect the vacuum level. There’s another reason; I don’t think it’s likely. Could it be that the main pipe for exhaust gases is under too much pressure, which prevents the gas pumped out by the pump from being released?